Jet propulsion outboard motor



Oct. 3l, 1950 R. M. FLANAGAN JET PROPULSION OUTBOARD MOTOR Filed Feb. 20. 1945 5 m 6 (2 m u2 www 0610 1 S 2 :N656 fw N/ .m//HHH l' 2 t 3 --QJ i.l l\.| 5 .nll J Ems 6 rimwL .m 6 rv3 u lln m M n /v 7 1 J l 1 m ww m l A. .o M .e F w Patented Oel. 31, 1950 mr rnorULsIoN ou'rnolllm Moron Reben Michael Flanagan, Glen Reek, N. J., as-

signor to Bendix Aviation Corporation, Teterboro, N. J., a corporation of Delaware Application February 20, 1945, Serial No. 578,830 1 Claim. (CL (l0-35.6)

The present invention relates to a novel means for propelling a. boat and more particularly to a novel outboard jet propulsion mechanism.

An object of the invention is to provide a novel propelling mechanism for a boat, including an air compressor directly driven by an internal combustion engine and supplying air to a combustion chamber in which chamber there is located a nozzle for admitting a combustible fluid and means for igniting or exploding the resultant mixture in the chamber so as to provide an exhaust jet for propelling the boat.

Another object of the invention is to provide a novel expansion type nozzle-in which the velocity energy of the exhaust gas is converted to pressure energy for propelling the boat.

Another object of the invention is to provide a novel proplllsion unit for a boat arranged so as to entrain a portion of the water in which the boat floats .by forcing exhaust gas into the throat of a suitable venturi tube carried by the boat and through which the water may flow.

Another object of the invention is to provide a novel manually operable means for controlling the direction of movement of the boatby changing the angle at which the venturi tube extends relative to the boat.

These and other objects and features of the invention are pointed out in the following description in terms of the embodiment thereof which is shown in the accompanying drawing. It is to be understood, however, that the drawing is for the purpose of illustration only, and is not designed as a definition of the limits of the invention, reference being had to the appended claim for this purpose.

Referring to the drawing:

Figure 1 is a vertical sectional view of a device embodying the invention;

Figure 2 is an end view of the venturi tube of Figure 1;

Figure 3 is a sectional view of Figure 1 taken along the lines 3-3 of Figure 1 and looking in the direction of the arrows.

As shown in Figure 1. there is provided an internal combustion engine I which may be oi conventional type including a cylinder II having a piston I2 slidably mounted therein. The piston I2 is connected through a piston rod I5 to a crank shaft I6 on which is mounted a ily wheel I1. An inlet passage I8 for the combustible fluid leads into the cylinder II from the crank case I9. The combustible fluid is fed into the crank case from a carburetor in a conventional manner. A spark plug 2l of conventional type and suitably electrically connected serves to ignite the combustible uid thus fed into the'cylinder II.

A casing enclosing the engine In has formed therein a tank 28 for holding a supply of the combustible fluid.

Leading from the cylinder II is a passage 30 forming an exhaust passage for the gases from the cylinder II and opening into an outlet conduit as will be explained.

The passages I8 and 30 are controlled by the piston I2 which is shown in a position opening the passage 30 to the exhaust gases within the cylinder II. A deflector 32 on the piston I2 deilects the incoming fuel gases from passage I8 to the opposite end of cylinder II.

At the outer end of the crank shaft I6 there is mounted a starting plate 32, of conventional type. At the opposite end of the crank shaft I6 there is provided. a torsional coupling 35 through which the crank shaft I 6 is drivingly coupled to a rotary vane type compressor indicated generally by the numeral 31 and which may be of a type such as shown in Gregg U. S. Patent No. 2,148,070, granted February 21, 1939. The compressor 31 has provided a casing l0 having air inlet ports indicated in dotted lines by the numeral 48a. The casing 40 is suitably fastened at the upper end to the lower open end of the casing 25. The compressor 31 also includes a rotor 42 having slots in which are slidably mounted the vanes 43 and 44 in a manner well knownin the art.

An air outlet opening 0b is provided in the casing I0 and leads from the compressor 31 to an outlet conduit 50. The outlet conduit 50 leads from the compressor 31 into a. chamber 5I formed in the upper end of a tubular member or casing 55. The upper end of the tubular member is fastened by bolts 56 to the lower end of the casing 40 and opening into the tubular member 55 is the2 exhaust passage 30 as shown in Figures 1 and A combustible iuid is conducted by suitable means including a conduit 60a, and fuelpump and pressure regulating valve, not shown, from the supply tank 28 into the chamber 5| a suitable nozzle 60. A spark plug 6I of conventional type and suitably electrically connected serves to ignite the combustible fluid and air mixture in the chamber 5I. The combustion in chamber 5I takes place continuously.

A tubular member B5 of reduced size leads from the lower end of the chamber 5L to a novel expanslon type nozzle 10 formed at the lower end of the member 55.

The nozzle 10 extends substantially at right angles to the tubular member 55 and has formed therein a, venturi tube 13 having a flared open end15 and a throat portion 16.

Concentrically mounted within the throat portion 15 isa tube or propulsion unit 80 having an open end 8| extending in the direction of the flared open end 15 of the venturi 13. The opposite end of the tube is closed at 85. The tube 80 is supported within the throat 16 of the venturi 13 by web members 81 and 88 projecting through from the upper and lower portions of the venturi 13 as shown in Figures 1 and 2.

About a, portion of the throat 16 is an annular chamber 90 into which there opens the lower end of the tubular member 65. There is further formed in the web members 01 and 68 passages 93 and 89, respectively, which lead from the annularA chamber into the tubular propulsion unit 80.

As will be seen from Figures 1 and 2, one end of the venturi 13 has a flared open end 15, while the opposite end 95 of the venturi 13 has openings at the opposite sides of the web members 61 and 08. as best shown in Figure 2.

v'I'hus water may enter the venturi through the open end 95 and pass out through the open flared end 15. Ports 96, formed in the venturi 13, serve as outlet openings for the exhaust gas in the tubular member 55 from the engine I0.

A bracket |00 which may be of conventional type is provided for fastening jet propulsion mechanism to the stern of a boat, indicated by the numeral |0|. The bracket |00 has a conventional fastening screw |02 for fastening the bracket to the boat and a swivel mounting |04 whereby the Jet propulsion mechanism is pivotally fastened to the bracket |00 for rotation of the mechanism on a vertical axis.

The swivel bolt |04 pivotally connects the mechanism to an arm |06 on a vertical axis, while the arm |06 is in turn pivotally connected to the bracket |00 on a horizontal axis by a swivel bolt |01.

A second adjustment nut |05 is provided for securing an adjustable plate lines by the numeral |05a relative to the bracket |00. The plate |05a is formed separate from the bracket |00 and jet propulsion mechanism. Through adjustment, of the mechanism around the horizontal axis of the swivel bolt |01 the angle at which the nozzle is positioned may be varied. The bracket |00 is connected to the jet propulsion mechanism through the swivel bolts |04 and |06 only and plate |05a merely acts as an adjustable support for the mechanism to determine the angle at Awhich the nozzle 10 is positioned about the horizontal axis |01. The bracket |00 and adjustable plate |05a are not xedly con` nected to the Jet propulsion mechanism.

A handle ||0 is fastened to thejet propulsion mechanism so that the same may be conveniently pivoted on the swivel mounting |04 for changing the direction of movement of the boat under force of the propelling exhaust jet.

The adjustable plate |05 as shown by dotted lines in Fig. 1 serves as an adjustable stop to limit adjustment of the jet propulsion mechanism about the swivel bolt |01 in a clockwise direction. The casing of the jet propulsion mechanism is not flxedly secured to the bracket |00 or plate |05a, but rather so bears upon the plate |05a that the mechanism may be conveniently pivoted on the swivel mounting |04, as previously described.

In the operation of the novel mechanism described, it will be seen that the internal combustion engine |0 drives the rotary vane type compressor 31 through the torsional coupling 35 and air under pressure of the compressor 31 flows into the combustion chamber 5|. A combustible fluid enters the chamber 5| through the nozzle 60 and is ignited through operation of the spark plug 6|.

The heat of combustion of the mixture inindicated in dotted l creases the volume of the air in proportion to the amount of combustible fluid introduced.

The increase. volume of air due to the rise in temperature resulting from combustion passes through the conduit and passages 90, 93. 99 and out the nozzle of the propulsion unit and venturi throat 16. The propulsion unit 80 is so designed that the velocity of the escaping gas approaches the expected maximum speed through the venturi throat 16. The gas escaping through the nozzle 10 under pressure effects a forward thrust due to the ejector action of the venturi tube 10 causing the boat to move through the water.

Moreover', by turning the mechanism in relation to the boat by operation of the lever I0, the direction of the thrust may be changed and thereby the direction of movement of the boat.

Although only one embodiment of the invention has been illustrated and described, various changes in the form and relative arrangements of the parts, which will now appear t0 those skilled in the art, may be made without departing from the scope of the invention. Reference is, therefore, to be had to the appended claim for a definition of the limits of the invention.

What is claimed is:

A mechanism for propelling a, boat, comprising, in combination, an internal combustion engine having an exhaust passage, a rotary air compressor driven by said engine, means for fastening said engine and compressor to the stern of a boat, a tubular member extending vertically downward from said engine and compressor, a combustion chamber provided within said tubular member and supplied with air under compression by said compressor, combustible fuel supply means for said chamber, ignition means for said combustible fluid, a venturi tube mounted at the lower end of said tubular member, said venturi tube having a throat portion and one end open through which water may be drawn, and an opposite open flared end through which the water may be expelled, a propulsion unit, a first conduit connecting said combustion chamber to said unit, said tubular member connecting said exhaust passage to said venturi tube and surrounding said first conduit, and said propulsion unit mounted in said throat portion for discharging a stream of combustlon products from said combustion chamber in such a manner as to 'force entrained water from the4 flared end of said venturivtube so as to exert a force for propelling the boat.

ROBERT MICHAEL FLANAGAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 368,678 McDougall Aug. 23, 1887 1,375,601 Morize Apr. 19, 1921 2,224,900 Conover Dec. 17, 1940 2,351,750 Fawkes June 20, 1944 2,397,654 Forsyth Apr. 2, 1946 2,412,825 McCollum Dec. 17, 1946 FOREIGN PATENTS Number Country n Date 118,123 Great Britain Aug. 16, 1218 518,485 France Mar. 26, 1921 279,107 Italy Oct. 30, 1930 

